Pump drive control



Jan. 17,1956 B. SHARE- 2,730,955

PUMP DRIVE CONTROL 2 Sheets-Sheet 1 Filed Sept. 10, 1952 Z INVENTgR.

jo INTO/QUE) Jan. 17, 1956 SHARE 2,730,955

PUMP DRIVE CONTROL Filed Sept. 10, 1952 2 Sheets-Sheet 2 Z IN VEN TOR.

A ff /z/vE) United States Patent PUMP DRIVE CONTROL Barnett Share,Jamaica Estates, N. Y.

Application September 10, 1952, Serial No. 308,857

8 Claims. (Cl. 103-113) This invention relates to controls for pumpdrives wherein a priming pump is driven from a main pump and, moreparticularly, to an automatic control, responsive to liquid pressure atthe main pump outlet, to control the driving connection of the primingpump from the main pump. This application is a continuation in part ofmy copending application Ser. No. 287,713,. filed May 24, 1952, and nowPatent No. 2,675,762, issued April 20, 1954.

Centrifugal pumps are frequently used for water extraction purposes, forexample, with a series of driven well-points designed to maintain thewater level of an area, such as an excavation, below a predeterminedlevel. In initiating the pumping action, it is necessary to prime thecentrifugal pump until a predetermined liquid pressure is developed atits outlet.

For this purpose, an auxiliary or priming pump is connected to thecentrifugal pump to evacuate air therefrom and thus provide for flow ofwater through the centrifugal pump. Most conveniently, these primingpumps are driven from the centrifugal pump so that the priming pump isstarted whenever the centrifugal pump is started.

While the priming pump can be continually operated all during the timethe centrifugal pump is operated, this is wasteful of power. Hence, manyarrangements have been devised for disconnecting the drive of thepriming pump after the centrifugal pump has begun to deliver water fromits outlet.

These prior disconnecting arrangements have included both manuallyoperable devices and automatically operable devices. Manually operabledevices are dependent upon the human element and thus reliability ofdisconnection of the priming pump at the proper time can be assured. Theautomatic devices hitherto proposed have been unduly complicated orexpensive, or have not been reliable.

In accordance with the present invention, a simple, inexpensive, andfully automatic priming pump drive control is provided which iseffective not only to disconnect the priming pump drive when priming ofthe centrifugal pump is no longer needed, but also to reconnect thepriming pump drive automatically whenever further priming is needed. Toassure reliability of operation, the actuation of the drive control ismade directly dependent upon the liquid pressure at the centrifugal pumpoutlet, this pres sure being a direct indication of whether or notpriming is needed.

More specifically, the priming pump is mounted for movement toward andaway from the main pump and driven from the latter by driving meanswhich must be maintained under tension to be effective.

The priming pump is swingably mounted in such manner that it is biasedby gravity away from the main pump. Means are provided, operatingdirectly in response to liquid pressure at the main pump outlet, toswing the priming pump, against the gravity bias, toward the main pumpto render the driving means ineffective. Thus,

ice

whenever the liquid pressure at the main pump outlet is at or above apre-set value, the priming pump drive is rendered ineffective, but thedrive is immediately and automatically made effective whenever suchoutlet pressure drops below such pre-set value. Other means, responsiveto liquid output from the main pump, interrupt the priming connection tothe priming pump When the main pump is delivering liquid.

For an understanding of the invention principles, reference is made tothe following description of a typical embodiment thereof as illustratedin the accompanying drawing. In the drawing:

Fig. 1 is a somewhat schematic elevation view, partly in section,illustrating the invention drive control in the priming position;

Fig. 2 is a similar view showing the control with the priming pump driveineffective; and

Fig. 3 is a view similar to Fig. 1, showing an alternative embodiment ofthe drive control.

Referring to Fig. l, a main centrifugal pump 10 is shown as supported ona suitable base 11. Pump 10, in the usual manner, has an axial inlet(not shown) and an outlet 12 connected to a chamber 13. A spring biasedvalve 15 closes the connection between outlet 12 and chamber 13 exceptat such times as the liquid pressure at the outlet equals or exceeds apre-set value. When the pressure attains this value, valve 15 is liftedso that liquid flows from outlet 12 into chamber 13 and out throughdischarge pipe 14.

in communication with the interior of pump it) and thus with outlet 12,is a float chamber 16. A float valve 2b is pivoted at 17 on the sidewall of the chamber 20, and carries a float 18. When the liquid inchamber 16 reaches a pre-set level, valve 2% is swung to close anopening 21 to a priming line 22 leading to the inlet 23 of a relativelysmall priming or auxiliary pump 25 having a discharge pipe 29.

Priming pump 25 is supported on a platform 24 to one end of which issecured a downwardly extending support 27 pivotally mounted in a bearing28 on platform 11. The pump is mounted in spaced relation to support 27so that the pump weight biases platform 2d counter-clockwise as viewedin the drawing figures.

To permit movement of pump 25 relative to pump 10, priming line 22 ismade partially or completely flexible. Pump 25 is driven from pump illby a belt 31 trained over a pulley 32, on the drive shaft of pump ill,and a pulley 33 on the drive shaft of pump 25. A guard 34- partiallysurrounds pulley 32, and a guard 36 surrounds pulley 33.

The drive control includes the valve 15 which has a stem 41 sliding in aguide 42 extending from cap 43 of chamber 13. A flexible cable,generally indicated at 45, has its casing 46 fastened to and sealed intoguide 42, the cable being clamped to cap 43 by clamp i l. Adjacent itsother end, cable 45 is secured firmly to platform ill by a clamp 47. Themovable core 5d of cable 45 is soldered or otherwise secured, at oneend, into valve stem il, so that core 50 moves, relative to casing 4d,whenever valve 15 moves. The other end of core 56} engages the undersideof the free end of platform 24, being held thereto by a clamp 48 securedby a bolt and nut arrangement $9.

in the off or starting conditions of pump iii, the components occupy thepositions shown in Fig. 1. Valve 15 is closed, so that cable core dd hasits free end drawn into casing 46 allowing platform 24 to be biasedcounterclockwise by the weight of pump 25.

When pump M is started, pump 25 is driven to draw the air from pump illand its connections through priming line 22, discharging this airthrough pipe 29. As pump 10 commences to deliver liquid, the liquidlevel in cham ber 16 rises sothat float valve 20 eventually closespriming line 22.

Meanwhile, fluid pressure builds up in outlet 12, and reaches thepre-set value at "which valve 15 lifts so that pump discharges throughpipe 14. As valve is lifted, core 50 of flexible cable '45 is moved toswing platform 24 clockwise. This moves pump 25 clockwise to remove thetension from belt 31, thus rendering the priming pump drive ineifective.Guardsf34, 36 prevent displacement of belt 31.

Should the outlet pressure drop sufficiently to allow valve 15 to beclosed by its spring, the valve pulls cable core 50 into chamber 13,allowing the weight of pump 25 to swing support 24 counter-clockwise toreestablish the driving connection between pumps 19 and 25.

- Fig. 3 shows an alternative embodiment in which flexi- -ble cable '45is replaced by a hydraulic system. In this case, a flexible conduitr55has one end fastened in and fluid-tightly sealed to guide 42. The otherend of conduit 55 is connected to a cylinder 56 mounted beneath the freeend of platform 24 and having a piston 57 engaging the underside of theplatform. Conduit 55, valve guide 42,

and cylinder 56 are filled with hydraulic pressure fluid so that, asvalve '15 is lifted, valve stem 41 acts as a piston to force hydraulicfluid into conduit 55. This forces piston 57 outwardly of cylinder 56 toswing platform 24 clockwise to disconnect the pump drive. When valve 15closes, the outward movement of valve stem 41 relative to guide 42allows hydraulic fluid to flow out of cylinder 56 into conduit 55. Theweight of pump 25 causes platform 24 to push piston 57 inwardly. Themovement of platform 24 reestablishes the pump driving connections.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the inventionprinciples, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

l. A pump drive control comprising, in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and aliquid inlet; a priming pump having a priming connection to said mainpump; a valve normally biased to close said outlet and having a stem onits outer face slidable in a guide, said valve being operable, uponattainment of a preset outlet pressure of 7 said main pump, to open andmove said stem through said guide; a tension driving meansinterconnecting said pumps for driving said priming pump from said mainpump; means mounting said priming pump for movement relative to saidmain pump; gravity influenced means biasing said priming pump away fromsaid main pump to maintain driving tension on said driving means; andmechanism,

establishing an operative connection between said valve stem and saidpump mounting means, operable, upon attainment of a pre-set outletpressure of said main pump, to move said priming pump toward said mainpump to remove the driving tension from said driving means.

2. A pump drive control comprising, in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and aliquid inlet; a priming pump having a priming connection to said mainpump; a valve normally biased to close said outlet and having a stem onits outer face slidable in a guide, said valve being operable, uponattainment of a preset outlet pressure of said main pump, to open andmove said stem through said guide; a tension driving meansinter-connecting said pumps for driving said priming pump from said mainpump; means mounting said priming pump for movement relative to saidmain pump; gravity influenced means biasing said priming pump away fromsaid main pump to maintain driving tension on said driving means;mechanism, establishing an operative connection between said valve stemand said pump mounting means, operable,

upon attainment-of a-pre-set outlet pressure of said main pump, to movesaid priming pump toward said main pump to remove the driving tensionfrom said driving means; and means operable responsive to delivery ofliquid from said main pump to interrupt said priming connection.

3. A pump drive control comprising, in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and aliquid inlet; a priming pump having a priming connection to said mainpump; a tension driving means inter-connecting said pumps for drivingsaid priming pump from said main pump; a platform pivotally supported atits end nearest said main pump, said priming pump being mounted on saidplatform between its supported and free ends and biasing said platformto swing its free end away from said main pump to maintain tension onsaid driving means; a valve biased to close said outlet until the mainpump delivery pressure attains a pre-set value; and a force-transmittingconnection between said valve and the free end of said platform andoperable,.when said valve opens responsive to said preset deliverypressure value, to swing said platform and priming pump toward the mainpump to remove the driving tension from said driving means.

4. A pump drive control, comprising, in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and aliquid inlet; a priming pump having a priming connection to said mainpump; a tension driving means inter-connecting said pumps for drivingsaid priming pump from said main pump; a platform pivotally supported atits end nearest said main pump; said priming pump being mounted on saidplatform between its supported and free ends and biasing said platformto swing its free end away from said main pump to maintain tension onsaid driving means; a valve biased to close said outlet until the mainpump delivery pressure attains a pre-set value; and a flexible cableextending between said valve and the free end of said platform andoperable, when said valve opens responsive to said pre-set deliverypressure value, to swing said platform and priming pump toward the mainpump to remove the driving tension from said driving means.

5. A pump drive control comprising, in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and aliquid inlet; a priming pump having a priming connection to said mainpump; a tension driving means inter-connecting said pumps for drivingsaid priming pump from said main pump; a platform pivotally supported atits end nearest said main pump; said priming pump being mounted on saidplatform between its supported and free ends and biasing said platformto swing its free end away from said main pump to maintain tension onsaid driving means; a valve biased to close said outlet until the mainpump delivery pressure attains a pro-set value; and a flexible cableextending between said valve and the underside of the free end of saidplatform and operable, when said valve opens responsive to said saidpre-set delivery pressure value, to swing said platform and priming pumptoward the main pump to remove the driving tension from said drivingmeans.

6. A pump drive control comprising, in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and a.liquid inlet; a priming pump having a priming connection to said mainpump; a tension driving means inter-connecting said pumps for drivingsaid priming pump from said main pump; a platform pivotally supported atits end nearest said main pump, said priming pump being mounted on saidplatform between its supported and free ends and biasing said platformto swing its free end away from said main pump to maintain tension onsaid driving means; a valve biased to close said outlet until the mainpump delivery pressure attains a pre-set value; and a hydraulic pressuresystem extending between said'valve and the free end of said platformand operable, when said valve opens responsive to said pre-set deliverypressure value, to swing said platform and priming pump toward the mainpump to remove the driving tension from said driving means.

7. A pump drive control comprising; in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and aliquid inlet; a priming pump having a priming connection to said mainpump; a tension driving means inter-connecting said pumps for drivingsaid priming pump from said main pump; a platform pivotally supported atits end nearest said main pump; said priming pump being mounted on saidplatform between its supported and free ends and biasing said platformto swing its free end away from said main pump to maintain tension onsaid driving means; a valve biased to close said outlet until the mainpump delivery pressure attains a pre-set value; and a hydraulic pressuresystem extending between said valve and the underside of the free end ofsaid platform and operable, when said valve opens responsive to saidpre-set delivery pressure value, to swing said platform and priming pumptoward the main pump to remove the driving tension from said drivingmeans.

8. A pump drive control comprising, in combination, a main pump fordisplacing liquid, and having an outlet for liquid under pressure and aliquid inlet; a priming pump having a priming connection to said mainpump, a tension driving means inter-connecting said pumps for drivingsaid priming pump from said main pump; a platform pivotally supported atits end nearest said main pump; saidpriming pump being mounted on saidplatform between its supported and free ends and biasing said platformto swing its free end away from said main pump to maintain tension onsaid driving means; a valve biased to close said outlet until the mainpump delivery pressure attains a pre-set value; said valve having astern engaged in a tubular stem guide; a cylinder having a pistonengaged with the underside of the free end of said platform; and ahydraulic pressure line inter-connecting said valve stem guide and saidcylinder; whereby, when said valve opens responsive to said pre-setdelivery pressure value, said piston will be projected to swing saidplatform and priming pump toward the main pump to remove the drivingtension from said driving means.

References Cited in the file of this patent UNITED STATES PATENTS1,107,533 Lorenz Aug. 18, 1914 1,949,428 McGee Mar. 6. 1934 2,675,762Share Apr. 20, 1954 FOREIGN PATENTS 253,205 Great Britain June 14, 1926396,218 Germany July 4, 1922 401,149 Germany Jan. 14, 1938

